1. Field of the Invention
The present invention relates to a surface treating process, and in particular, a surface treating process for forming a deposited film of a metal such as aluminum, zinc and tin, or a metal nitride such as titanium nitride on the surface of a sintered product such as, for example, a rare earth metal-based magnet liable to be oxidized, and the like, thereby ensuring that the sintered product such as the rare earth metal-based magnet has an oxidation resistance.
In more particular, the present invention relates to a surface treating process capable of surface-treating a large number of works collectively and uniformly such as a sintered product, e.g., a rare earth metal-based magnet having a shape having an inside diameter portion such as a ring-like shape and the like, and to a surface-treating support member, a surface treating holder and a surface treating apparatus which are suitable for use in such process.
2. Description of the Related Art
For example, in a conventional surface treating process for a rare earth metal-based magnet, a vacuum vapor-deposition apparatus 120 as shown in FIG. 11 was used to carry out a vapor deposition of aluminum. In FIG. 11, reference character 121 designates a vacuum treating chamber which can be maintained at a predetermined degree of vacuum through a vacuum pump 122. In the vacuum treating chamber 121, aluminum 123, which is an evaporation source, is heated within an evaporation source holder 124 by a heater 125. A rare earth metal-based magnet article 130 as a work is accommodated in a cage-like container 126, and the vapor deposition of aluminum is carried out, while rotating the container 126, thereby uniformly depositing aluminum on the rare earth metal-based magnet article 130 as the work.
In the above conventional surface treating process, however, the substantially uniform vapor-deposition can be performed certainly. However, because the works are piled one on another within the cage-like container, it cannot be avoided that some deposition nonuniformity is produced. Therefore, it has been desired to propose a surface treating process by which a further uniform surface treatment can be performed. Many of rare earth metal-based magnet articles such as Ndxe2x80x94Fexe2x80x94B based magnet articles, for example, resulting from the processing treatment, are rectangular parallelepiped, hard and moreover, have sharp corners. For this reason, the following problem is arisen: The corners collide with one another during the vapor deposition treatment, whereby the deposited film on the surface is peeled off and in a severe case, the corners of a product are chipped, resulting in a poor yield. Particularly, in a case of a large-sized article, there is a problem that the weight is large, and the collision energy is large, resulting in an extremely reduced yield. In a case of a work having an inside diameter portion and having a shape such as a ring-like shape and the like, there is a disadvantage that the inside diameter side of the work is occluded by the other work and for this reason, the uniform surface treatment of the inside diameter side cannot be achieved successfully.
Accordingly, it is an object of the present invention to provide a surface treating process, wherein the problems and disadvantages associated with the conventional process can be overcome, and even a plurality of works each having an inside diameter portion and having a shape such as a ring-like shape and the like can be uniformly surface-treated collectively.
As a result of zealous reviews, the present inventors have found that the surface treatment of works such as a vapor deposition meeting the above requirement can be carried out in a state in which the works has been spaced apart from one another, while rotating the works about their axes, or rotating the works about a rotational axis, or rotating the works about the rotational axis and about their axes.
To achieve the above object, according to a first aspect and feature of the present invention, there is provided a surface-treating support member for supporting a plurality of works, comprising an upper cage and a lower cage including a large number of compartments, so that the cages are openable and closable in a lengthwise direction.
With the above feature, the surface-treating support member is comprised of the upper and lower cages including the large number of compartments, so that the cages are openable and closable in the lengthwise direction. Therefore, the works can be accommodated into the cage-like compartments at distances and removed from the cage-like compartments by opening and closing the upper and lower cages.
The shape, mesh size and the like of each cage may be selected properly, so that clearances can be formed at a size enough to ensure that a surface-treating material can reach works sufficiently and uniformly in correspondence to the size and shape of the work.
According to a second aspect and feature of the present invention, there is provided a surface-treating support member for supporting a plurality of works each having an inside diameter portion, comprising plate-like elements openably and closably foldable in a lengthwise direction, the plate-like elements being capable of defining a plurality of narrow sections each having a length corresponding to the inside diameter of the work in opened states.
According to a third aspect and feature of the present invention, in addition to the second feature, the plate-like elements are openably and closably foldable by a hinge.
With the above features, the surface-treating support member is comprised of plate-like elements openably and closably foldable in a lengthwise direction, so that the plurality of narrow sections each having a length corresponding to the inside diameter of the work can be defined in the opened state. Therefore, works can be set respectively in the narrow sections in the folded states of the plate-like elements, and then supported in spaced-apart states in the narrow sections by folding up the plate-like elements. After the surface treatment, the works can be easily removed from the support member by folding the plate-like elements again.
Particularly, by ensuring that the plate-like elements can be openably and closably folded by the hinge, it is easy to mount and remove the works to and from the support member.
The shape, size and the like of each of the narrow sections may be selected, so that the works can be maintained in the spaced-apart states in correspondence to the size and shape of the work.
According to a fourth aspect and feature of the present invention, there is provided a surface treating holder comprising a wire which is coiled at distances in such a manner that it is formed as a spring-like tubular structure having spiral-line faces at opposite ends thereof, so that works can be accommodated in the tubular structure.
According to a fifth aspect and feature of the present invention, in addition to the fourth feature, the tubular structure is a cylindrical structure.
According to a sixth aspect and feature of the present invention, in addition to the fourth feature, an entanglement preventing spring is wound around that portion of the wire which forms the side face of the tubular structure.
According to a seventh aspect and feature of the present invention, in addition to the fourth feature, the wire is closely wound in the vicinity of opposite ends of a side face of the tubular structure.
According to an eight aspect and feature of the present invention, in addition to the fourth feature, the central portion of the wire is closely wound at locations corresponding to the spiral-line faces of the tubular structure.
According to a ninth aspect and feature of the present invention, in addition to the fourth feature, the wire is formed of a stainless steel.
In the surface-treating holder, the wire is coiled at distances in such a manner that it is formed as the spring-like tubular structure having spiral-line faces at opposite ends thereof, so that the works can be accommodated in the tubular structure. Therefore, the uniform surface treatment such as vapor deposition of aluminum can be carried out from the clearances defined by the wire. In addition, even when the holders collide with one another, the works within the holders cannot collide with one another. Moreover, no large shock cannot be applied to the work within the holder by the aid of a spring property possessed by the holder and hence, the peeling-off of a treated surface, the chipping of a product and the like cannot be produced. The work can be placed into and removed from the holder through the clearances defined by the wire by utilizing the spring property and thus, special inlet and outlet are not required.
The diameter, number of turns and pitch of turns of the wire may be selected properly, taking account of the formation of the clearance having a size enough to enable the appropriate spring property and the fact that the surface treating material can reach the work sufficiently and uniformly.
If the holder is tubular, the shape of the holder is particularly not limited, and the holder may be elliptical. However, if it is taken into consideration that the holder can be easily rotated, and that the material is deposited uniformly, it is preferable that the holder is cylindrical.
In addition, by winding the entanglement preventing spring around that portion of the wire which forms the side face of the tubular structure, the wires forming the holders can be prevented from entering a clearance defined between both of the wires, whereby the entanglement of the wires forming the holders with one another is prevented.
The entering of the wires forming the holder into the clearance defined between both of the wires can be inhibited likewise even by closely coiling the wire in the vicinity of the opposite ends of the side face of the tubular structure, or by closely coiling the central portion of the wire at the opposite spiral-line faces of the tube, whereby the entanglement of the wires forming the holders with one another is prevented. This ensures that the uniform surface treatment such as vapor deposition of aluminum is feasible.
By forming the wire from a stainless steel, for example, aluminum or the like deposited on the wire can be washed off by an acid. In addition, the spring property is not damaged even by the vapor deposition carried out at a high temperature, unlike iron.
In this way, if the surface treatment such as vapor deposition of aluminum is carried out in a state in which a work comprising a rare earth metal-based magnet has been accommodated in the surface treating holder having the above-described arrangement, the uniform surface treatment as ever can be achieved through the clearances defined by the wire, and moreover, the peeling-off of the treated surface, the chipping of a product and the like cannot be produced, leading to an excellent yield.
According to a tenth aspect and feature of the present invention, there is provided a process for surface-treating a plurality of works, comprising the step of surface-treating the works in a treating chamber, while rotating the works about their axes in spaced-apart states.
According to an eleventh aspect and feature of the present invention, in addition to the tenth feature, the surface treatment is a vapor deposition on a sintered article.
According to a twelfth aspect and feature of the present invention, in addition to the tenth feature, the rotation of the works about their axes is conducted with the works supported by a support member rotated about its axes.
According to a thirteenth aspect and feature of the present invention, in addition to the twelfth feature, the surface treatment is a vapor deposition on a sintered article.
According to a fourteenth aspect and feature of the present invention, in addition to the twelfth feature, a support member according to the first feature is used.
According to a fifteenth aspect and feature of the present invention, in addition to the fourteenth feature, the surface treatment is a vapor deposition on a sintered article.
According to a sixteenth aspect and feature of the present invention, in addition to the twelfth feature, a support member according to the second feature is used.
According to a seventeenth aspect and feature of the present invention, in addition to the sixteenth feature, the surface treatment is a vapor deposition on a sintered article.
According to an eighteenth aspect and feature of the present invention, in addition to the tenth feature, each of the works is accommodated in corresponding one of holders according to the fourth feature, and the holders are rotated about their axes within a porous cage-like rotatable member.
According to a nineteenth aspect and feature of the present invention, in addition to the eighteenth feature, the surface treatment is a vapor deposition on a sintered article.
According to a twentieth aspect and feature of the present invention, there is provided a process for surface-treating a plurality of works, comprising the step of surface-treating the works, while rotating them about a rotational axis in spaced-apart states.
According to a twenty first aspect and feature of the present invention, in addition to the twentieth feature, the surface treatment is a vapor deposition on a sintered article.
According to a twenty second aspect and feature of the present invention, in addition to the twentieth feature, the rotation of the works about their axes is carried out with the works supported by a support member rotated about a rotational axis.
According to a twenty third aspect and feature of the present invention, in addition to the twenty second feature, the surface treatment is a vapor deposition on a sintered article.
According to a twenty fourth aspect and feature of the present invention, in addition to the twenty second feature, a support member according to the first feature is used.
According to a twenty fifth aspect and feature of the present invention, in addition to the twenty fourth feature, the surface treatment is a vapor deposition on a sintered article.
According to a twenty sixth aspect and feature of the present invention, in addition to the twenty second feature, a support member according to the second feature is used.
According to a twenty seventh aspect and feature of the present invention, in addition to the twenty sixth feature, the surface treatment is a vapor deposition on a sintered article.
According to a twenty eighth aspect and feature of the present invention, there is provided a process for surface-treating a plurality of works, comprising the step of surface-treating the works, while rotating them about their axes and about a rotational axis in spaced-apart states.
According to a twenty ninth aspect and feature of the present invention, in addition to the twenty eighth feature, the surface treatment is a vapor deposition on a sintered article.
According to a thirtieth aspect and feature of the present invention, in addition to the twenty eighth feature, the rotation of the works about the rotational axis conducted while being rotated about their axes is carried out with the works supported by a support member rotated about a rotational axis and about its axis.
According to a thirty first aspect and feature of the present invention, in addition to the thirtieth feature, the surface treatment is a vapor deposition on a sintered article.
According to a thirty second aspect and feature of the present invention, in addition to the thirtieth feature, a support member according to the first feature is used.
According to a thirty third aspect and feature of the present invention, in addition to the thirty second feature, the surface treatment is a vapor deposition on a sintered article.
According to a thirty fourth aspect and feature of the present invention, in addition to the thirtieth feature, a support member according to the second feature is used.
According to a thirty fifth aspect and feature of the present invention, in addition to the thirty fourth feature, the surface treatment is a vapor deposition on a sintered article.
In the above process for surface-treating the plurality of works, the surface treatment of the works is carried out in the treating chamber in spaced-apart states, while rotating the works about their axes, or rotating the works about the rotational axis, or rotating the works about their axes and about the rotational axis. Therefore, the entire surfaces of the works can be treated uniformly and simultaneously.
Thus, by such uniform surface treatment of the works in the spaced-apart states, a film of a soft metal such as aluminum, tin and zinc or a hard metal nitride such as titanium nitride can be deposited uniformly even on a hard and brittle sintered article.
The rotation of the works about their axes, or about the rotational axis, or about their axes and about the rotational axis can be reliably achieved by supporting the works by the support member rotated about its axis, or about the rotational axis, or about its axis and about the rotational axis.
In this case, the works can be rotated about their axes, or about the rotational axis, or about their axes and about the rotational axis in the spaced-apart states by use of the surface-treating support member according to the above-described feature of the present invention. When the surface-treating support member is used which is comprised of the upper and lower cages including the cage-like compartments, so that the cages are openable and closable in the lengthwise direction, the works can be treated, irrespective of the shape of the works and particularly, even if they are large-sized.
In addition, by using the surface-treating support member which is comprised of the plate-like support elements openably and closably foldable in the lengthwise direction, so that the plurality of narrow sections each having a length corresponding to an inside diameter of a work having an inner diameter portion are defined in the opened states of the plate-like elements, the works having the inside diameter portion and having a disk-like shape or the like can be rotated about their axes, or about the rotational axis, or about their axes and about the rotational axis, while being reliably maintained in the spaced-apart states. Particularly, when the works are supported at the inside diameter in the above manner, the works can be orientated vertically in the lengthwise direction with respect to the treating material source such as a vapor deposition source. Moreover, the reaching of the treating material to the surfaces of the works cannot be blocked, except for the inside diameter-supported points of the works, whereby a very efficient surface treatment can be achieved. Therefore, a vacuum deposition in a short time is feasible, and the surface treatment can be finished before rising of the temperature. The surface treatment of, for example, an Ndxe2x80x94Fexe2x80x94B rare earth metal-based sintered magnet article can be achieved in one run with a very good efficiency at a temperature of 400xc2x0 C. or less at which the magnetic property is not degraded. The inside diameter-supporting is by point contact, and the point contact sites are moved properly, whereby the entire inside diameter is surface-treated.
Moreover, in this case, if the vapor deposition is carried out in a state in which the negative pole has been connected to the support member; the works have been placed in their insulated states, and the vapor deposition source has been connected to a positive pole, the uniform surface treatment can be performed for the inside diameter side. It is convenient that the negative pole is connectable to the works through the means for rotating the works about their axes, because the negative pole can be connected to the works, when a surface cleaning treatment is to be conducted with argon gas.
The rotation of the works about their axes can be also performed by a method other than use of the support member, for example, by accommodating the works in the surface-treating holders and rotating the holders about their axes within a porous cage-like rotatable member.
The surface treatment is applicable to the formation of a film by a vapor deposition process and is suitable for depositing any of a metal, a non-metal inorganic substance, an organic compound and the like. The surface treatment is applicable to a vacuum deposition process, an ion sputtering process, an ion plating process, a vapor deposition polymerization and the like.
According to a thirty sixth aspect and feature of the present invention, there is provided a surface treating apparatus, comprising a treating material source provided within a treating chamber, so that a treating material released from the treating material source is delivered to reach works for a surface treatment, and a means for rotating a support member supporting the works about its axis.
According to a thirty seventh aspect and feature of the present invention, in addition to the thirty sixth feature, the surface treating apparatus is a vapor deposition apparatus.
According to a thirty eighth aspect and feature of the present invention, there is provided a surface treating apparatus, comprising a treating material source provided within a treating chamber, so that a treating material released from the treating material source is delivered to reach works for a surface treatment, and a means for rotating a support member supporting the works about a rotational axis.
According to a thirty ninth aspect and feature of the present invention, in addition to the thirty eighth feature, the surface treating apparatus is a vapor deposition apparatus.
According to a fortieth aspect and feature of the present invention, there is provided a surface treating apparatus, comprising a treating material source provided with in a treating chamber, so that a treating material released from the treating material source is delivered to reach works for a surface treatment, and a means for rotating a support member supporting the works about its axis and about a rotational axis.
According to a forty first aspect and feature of the present invention, in addition to the fortieth feature, the surface treating apparatus is a vapor deposition apparatus.
According to a forty second aspect and feature of the present invention, in addition to the fortieth feature, the apparatus further includes at least two rotary plates, on which receiving elements for support members for supporting the works are disposed in a circumferential direction, so that the support members can be supported between the at least two rotary plates through the receiving elements, whereby the support members can be rotated about their axes by the rotation of the receiving elements and rotated about the rotational axis by the rotation of the rotary plates.
According to a forty third aspect and feature of the present invention, in addition to the forty second feature, the surface treating apparatus is a vapor deposition apparatus.
According to a forty fourth aspect and feature of the present invention, in addition to the fortieth feature, the apparatus further includes a means for transmitting a driving force provided by a driving shaft for rotating the support member about the rotational axis to the support member, as a driving force for rotating the support member about its axis.
According to a forty fifth aspect and feature of the present invention, in addition to the forty fourth feature, the surface treating apparatus is a vapor deposition apparatus.
The above-described surface treating apparatus includes the means for rotating the support member for supporting the works about its axis, the means for rotating the support member for supporting the works about the rotational axis, or the means rotating the support member for supporting the works about its axis and about the rotational axis. Therefore, by transporting the surface-treating support member into the treating chamber to set it in the treating chamber, the plurality of works can be surface-treated simultaneously and uniformly, while being rotated about their axes, or about the rotational axis, or about their axes and about the rotational axis in spaced-apart states.
In the surface treating apparatus, the support members can be supported through the receiving elements between the at least two rotary plates on which the receiving elements for supporting the works are disposed in the circumferential direction. In addition, in the surface treating apparatus, the support members can be rotated about their axes by the rotation of the receiving elements and rotated about the rotational axis by the rotation of the rotary plates. Therefore, the plurality of works can be surface-treated simply utilizing the conventional vapor deposition apparatus, while being rotated about their axes, or about the rotational axis, or about their axes and about the rotational axis in the spaced-apart states.
The surface treating apparatus is applicable to the formation of a film by a vapor-phase growth process, and more particularly, examples of such apparatus are a vacuum vapor deposition apparatus, an ion sputtering apparatus, an ion plating apparatus, and a vapor deposition polymerizing apparatus.
The above and other objects, features and advantages of the invention will become apparent from the following description of the preferred embodiment taken in conjunction with the accompanying drawings.